These are just the run of the mill later model castings.  Not sure where they were originally cast but thought that these were cast in the U.S.  Small valves and big chambers.  Nothing fancy, just new old stock.

Lorena, Texas (South of Waco)

Ted: Would those be the nos heads that came out of Argentina? If so they are available from Dennis Carpenter in N.C. Apparently they are good quality castings, but unfortunately they use the smallest intake valves. However, John Mummert offers 1.84" diameter intakes for them, if anyone is interested. I seem to recall that possibly Doc Frohmader (?) said the decks were fairly thick on them, if so they may be suitable for milling down. However, I'm not sure of that last info.

Paul

As Mike mentions, the part number C3TZ-G heads are of the larger chamber design.  Thanks Mike.

Lorena, Texas (South of Waco)

C3TZ part number, C1TE casting number, 76 cc.

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

hi Ted, have you seen a set of these heads, ebay item #230319092738, C3TZ-6049-G, they look like they have small cumbustion chambers, thanks, wayne.

 lincoln/merc. y-blocks &mel's                                                               bucyrus, ohio.